I have for my main and only character and some of the BOFF. Though I plan to write something about every single BOFF as well. Sometimes I do click on other people to see if they have a bio written but very few do. The game is far more interesting when your character has a back story - doesn't have to be a legendary one, he/she could be just an average person who happened to be a Captain. Mine is a male Betazoid born & raised on Earth whose parents left their homeworld to pursue careers on Broadway in NYC. In many ways, he is very human because Earth is where he grew up except his unique biology.
Funny enough, having a pure race character in game (as opposed to so many composite "Alien" out there) seemed to gain a tremendous amount of support from the character's homeworld. Not sure about others but whenever some assignments have to do with Betazed or Betazoid Government, the rewards most often end up being Purple / Very Rare items like DOFF and/or BOFF. Take example of the Cultural Exchange assignments, never got anything except white / common doff from all other planets like Vulcan, Trill, Bolian and etc. Did it once with Betazed, and even with merely a "Success", not even "Critical Success", was awarded a Purple / Very Rare Biochemist DOFF. The first BOFF who applied to join my crew through assignments was also on the "request" of the Betazoid Government, suffice to say, this guy is now my chief Science officer and has been ever since. That was the only time however, they rarely contact me. Subsequently, I got numerous requests from all kinds of Fed Governments, like the truck load of Human applicants - never got anyone interesting, pretty much stop accepting their requests as a waste of my time / assignment slot.